{ config, lib, pkgs, ... }: with lib; let pkg = if config.hardware.sane.snapshot then pkgs.sane-backends-git else pkgs.sane-backends; sanedConf = pkgs.writeTextFile { name = "saned.conf"; destination = "/etc/sane.d/saned.conf"; text = '' localhost ${config.services.saned.extraConfig} ''; }; netConf = pkgs.writeTextFile { name = "net.conf"; destination = "/etc/sane.d/net.conf"; text = '' ${lib.optionalString config.services.saned.enable "localhost"} ${config.hardware.sane.netConf} ''; }; env = { SANE_CONFIG_DIR = config.hardware.sane.configDir; LD_LIBRARY_PATH = [ "${saneConfig}/lib/sane" ]; }; backends = [ pkg netConf ] ++ optional config.services.saned.enable sanedConf ++ config.hardware.sane.extraBackends; saneConfig = pkgs.mkSaneConfig { paths = backends; }; enabled = config.hardware.sane.enable || config.services.saned.enable; in { ###### interface options = { hardware.sane.enable = mkOption { type = types.bool; default = false; description = '' Enable support for SANE scanners. Users in the "scanner" group will gain access to the scanner, or the "lp" group if it's also a printer. ''; }; hardware.sane.snapshot = mkOption { type = types.bool; default = false; description = "Use a development snapshot of SANE scanner drivers."; }; hardware.sane.extraBackends = mkOption { type = types.listOf types.path; default = []; description = '' Packages providing extra SANE backends to enable. The example contains the package for HP scanners. ''; example = literalExample "[ pkgs.hplipWithPlugin ]"; }; hardware.sane.configDir = mkOption { type = types.str; internal = true; description = "The value of SANE_CONFIG_DIR."; }; hardware.sane.netConf = mkOption { type = types.lines; default = ""; example = "192.168.0.16"; description = '' Network hosts that should be probed for remote scanners. ''; }; services.saned.enable = mkOption { type = types.bool; default = false; description = '' Enable saned network daemon for remote connection to scanners. saned would be runned from scanner user; to allow access to hardware that doesn't have scanner group you should add needed groups to this user. ''; }; services.saned.extraConfig = mkOption { type = types.lines; default = ""; example = "192.168.0.0/24"; description = '' Extra saned configuration lines. ''; }; }; ###### implementation config = mkMerge [ (mkIf enabled { hardware.sane.configDir = mkDefault "${saneConfig}/etc/sane.d"; environment.systemPackages = backends; environment.sessionVariables = env; services.udev.packages = backends; users.groups.scanner.gid = config.ids.gids.scanner; }) (mkIf config.services.saned.enable { networking.firewall.connectionTrackingModules = [ "sane" ]; systemd.services."saned@" = { description = "Scanner Service"; environment = mapAttrs (name: val: toString val) env; serviceConfig = { User = "scanner"; Group = "scanner"; ExecStart = "${pkg}/bin/saned"; }; }; systemd.sockets.saned = { description = "saned incoming socket"; wantedBy = [ "sockets.target" ]; listenStreams = [ "0.0.0.0:6566" "[::]:6566" ]; socketConfig = { # saned needs to distinguish between IPv4 and IPv6 to open matching data sockets. BindIPv6Only = "ipv6-only"; Accept = true; MaxConnections = 1; }; }; users.users.scanner = { uid = config.ids.uids.scanner; group = "scanner"; }; }) ]; }